This is truly a rare bird...
 
America entered the first World War near its close, and they quickly realized the army they possesed was a relic of the last century.  Amongst a variety of other problems they were facing, issuing their soldiers with the newely invented wristwatch was something that was not a standard issue item.  This my friends, is the an original American ancestor to every future wristwatch ever made...
 
The black star dial watch was something that was not sold by the government. It was an item that was given the nod of approval by the ordinance department and left to its own devices in the early years.  These watches could be purchased at post offices or on military bases as a private purchase. However, with research from Stan Czubernat's book "Elgin: Trenchwatches of the Great War" the specifications for an Army issued trench watch match this one on all accounts.
 
"U.S. Army-Issued Elgins had solid nickel, semi-hermetic cases... Made by Joseph Fahys and Company..."
 
Check...
 
"Elgin Factory date-stamp on the back side of the enamel dial"
 
Check...
 
The watch was powered by a seven-jewel movement
 
Check...
 
What you have here is a very rare bird, all original and running beautifully as I wear it upon my wrist as I write this and is keeping very good time for a 100 year old wonder. 
 
The strangest part of this story is the month I opened it, 10-18. Potentially 100 years after the dial was originally placed on this movement.  Lastly, the name "Shellhouse is inscribed on the insdide of the Fahys case which is too little information to track, but enough to give this watch a small piece of identity to another possible on its original steward.  I wonder what this watch has seen in its century of life, and how it will be celebrated for another 100 years to come...